This invention relates to solid propellant compositions and to a novel family of plasticizers for use therewith. In a more specific aspect, this invention concerns itself with the use of a novel family of azido nitramino ethers as energetic plasticizers for advanced solid propellant compositions. In still another specific aspect, this invention concerns itself with the use of azido nitramino ethers as a means of reducing or minimizing the amount of flame in the exhaust gases generated during the propulsion phase of solid propellants.
The increased utilization of propellant compositions has spawned a considerable research effort in an attempt to improve their performance characteristics. Generally, solid propellants consist of one or more organic or inorganic oxidizers dispersed in a resinous binder matrix which may also function as a fuel. Typical oxidizers are ammonium perchlorate or HMX (cyclotetramethylene tetranitramine), both of which are well known in the art. Various resinous components, such as hydrocarbons, polyesters, polyurethanes and other like materials serve as the binder/fuel matrix. A supplemental fuel component, such as finely powered aluminum, may be used also. Other additive components, such as anti-oxidants, burning rate modifiers, wetting agents, anti-foaming agents and plasticizers may be added to the propellant composition, if desired. Dibutylphthalate or triacetin are generally employed as inert plasticizers in combination with the resinous binder material.
In using solid propellants, however, a problem exists in that an undesirable amount of flame is often produced in the exhaust gases during their operational phase. Excessive amounts of flame are extremely undesirable in the exhaust gases since this provides data which pinpoints the sites from which propellant operated guns, missiles or rockets are being fired. As a consequence, a continuing research effort has been maintained in an attempt to provide solid propellants with a minimum amount of flame in their exhaust gases. In furthering the research effort referred to above, it was unexpectedly discovered that a new family of azido nitramino ethers could be employed as energetic plasticizers in the fabrication of solid propellants. These novel plasticizers replace the conventional inert plasticizers generally utilized in conventional composite propellants. The resulting propellants produce a minimum amount of flame during operation.